Vacuum-insulated terminal



June 16, 1925.

w. G. HOUSKEEPER E T Al.

lvAcUuM INSULATED TERMINAL Filed NOV. 19 1920 Patented June 16, 1925.

UNITED STATES PATENT OFFICE.

WILLIAM G. HOUSXEEPER, OF NEW YORK, N. Y., AND WILLIAM Bf. BROUGH, OF EAST ORANGE, NEW JERSEY, ASSIGNORS T WESTERN ELECTRIC COMPANY, INCOR- POBATED, 0F NEW YORK, N. Y., A CORPORATION OF NEW YORK.

vACU'UM-INSULATED TERMINAL.

Application led November 19, 1920. Serial No. 425,110. ci

T o all whom t may concern.'

Be it known that we, WILLIAM G. Hons- KEEPER and WILLIAM R. BROUGH, citizens of the United States, residing at New York, in the county of New York and State of New York, and at East Orange, in the count'y of Essex, State ofNew Jersey, respectively, have invented certain new and useful Improvements in Vacuum-Insulated Terminals, of which the following is a full, clear, concise, and exact description.

This invention relates to vacuum tubes of the electron discharge type and pertains more especially to an arrangement of the lead wires for the electrodes thereof.

In employing a vacuum tube in certain installations particularly in high voltage, high frequency circuits it is necessary to provide special means for preventing corona effects along the lead wires for the grid and anode electrodes and discharges from said lead wires to the base of the tube or to the lead wires of the cathode. Heretofore, attempts have been made to prevent thesee'ects by surrounding the lead wires of the anode and grid With bodies of insulating material extending through the disc forming the bottom of the base for the tube. However, the dielectric losses due to the high voltage, high frequency currents produced sulicient heating of the insulating bodies to quickly destro their insulating property and render the tu e inoperative.

It is the object of this invention effectively to prevent discharges from and corona effects on the leading in wires for the grid and anode electrodes of electron discharge devices.

For convenience this invention will be illustrated and described in connection with a tube of the three electrode type comprising an anode, a cathode and a control or grid electrode enclosed in an evacuated vessel.

The object of this invention is accomplished by providing in the stem of the vacuum tube one or more tubular members, the inner ends of which communicate with the interior of the tube andthe outer ends of which extend through the base of the tube. The lead wires of the anode and control electrode pass through these tubular members and are sealed into the outer ends thereof which are provided with suitable Contact thimbles to which the lead wires are electrically connected.

Referring now to the drawings, the single figure thereof discloses an electron discharge device of the three-electrode type embodymg the invention.

The vacuum tube com rises the bulb 10 having a cylindrical nec 11 which is returned into the tube to form the stem l2 in a well-known manner. Encircling the stem 12 is a corrugated metal collar 13 from which the members 14 extend into the center of the bulb 10. Supported by the members 14 is the substantially c lindrical anode 15 which supports the bloc s 16 of insulating material between which are carried the cathode 17 and the grid or control electrode 18 in the manner disclosed in the copending application of W. G. Houskeeper, Serial No. 3977 64 tiled July 20, 1920.

The base of the tube comprises a metallic cylindrical shell 19 having a spun over edge 20 which ts in a groove on the periphery of the disk 21 of insulating material. This base is cemented to t-.he neck of the vacuum tube as at 22 and the disc 2l is provided with four apertures for a purpose to be later described.

lVithin the stern 12 are arranged the tubular members 23 and 24 the inner ends of which communicate with the interior of the bulb 10 and the outer ends of which extend through certain of the apertures in the disc 21. The lead wires 25 and 26 of the anode and grid respectively, pass through the tubular members 23 and 24 and are sealed into the outer ends thereof. Arranged at the extremities of the tubular members 23 and 24 are the contact thimbles 27 and 28 whichl are cemented thereto and to which the lead wires 25 and 26 are electricall connected. The lead wires 29 of the catho e are sealed into the upper end of the stem as at 30 and extend to the contact members 31 arranged in the remaining apertures of the disk 21. These lead Wires are preferably enclosed in glass tubes 32.

The evacuated condition of the tubular members 23 and 24 surrounding the lead wires 25 and 26 effectively prevents the heating of the material of said members and also of the disk 21 since there is no gaseous medium within said members to carry electriral charges. The breaking down of the insulation due to heating ot the dielectric is thereby prevented. There is. therefore. no leakage through the walls of the tubular members and dislt and discharges from the lead wires to the shell l5) and the wires 2S) oll th(l cathode are prevented. ln addition. the development oi corona etl'ccts along any portion oi the lead wires 25 and 2li is prt vented by the vacuum surrounding them.

lt will be noted that the terminals 9.7 and 28 for the grid and anode lead Wires are of relatively large diameter and extend a relatively great distance beyond the base, Whereas the cathode terminals are of relatively small diameter and extend but a short distance beyond the base. The large diameter ot the grid and anode terminals decreases the intensity et the fields due to their potentials, and the short length of the cathode terminals produces a relatively long distance between them and the other terminals. The possibility ot discharges between the various terminals is thus prevented.

lt is, of course, understood that modifications may be made in the structure of this device without in any Way departing from the spirit of the invention as defined in the appended claims.

lVhat is claimed is:

l. An electron discharge device comprising an evacuated vessel having a stem, a base enclosing a portion of said vessel, an electrode supported by said stem, a tubular member Within said stem communicating with said vessel and extending through said base and a lead Wire for said electrode passing through said tubular member and being sealed into the outer end thereof.

2. A11 electron discharge device comprising an evacuated bulb having a stem, a base enclosing a portion of said bulb, an electrode supported within said bulb, an evacuated member extending through said base and a lead Wire Yfrom said electrode passing through said evacuated member.

An electron discharge device comprising an evacuated bulb having a stem, a base enclosing a portion of said bulb, an electrode supported by said stem, a tubular melnber within said stem opening into said bulb and extending through said base, a lead Wire for said electrode passing through said tubular member and being sealed into the outer end thereof and a contact thimble carried by the sealed end of said evacuated member, said thimble being electrically connected with said lead Wire.

4. An electron discharge device comprising an evacuated vessel having a stem, a base enclosing a portion of said vessel, an electrode supported Within said Vessel, an evacuated member extending through said base, a lead Wire tor said electrode passing through said evacuated member and a contact thimble carried by the end of said member projecting beyond said base, said thimble being electrically connected with said lead wire.

5. In an electron discharge device having cathode, grid and anode electrodes, a base, terminals for said grid and anode electrodes on said base comprising members extending a relatively great distance beyond the sur face of the base and of relatively large diameter and terminals for said cathode comprising members extending a relatively short distance beyond the surface of the base and of relatively small diameter.

In witness whereof, We hereunto subscribe our names this 10th day of November A. D.,

WILLIAM G. HOUSKEEPER. WILLIAM R. BROUGH. 

